Topics to be taught at our October Class

Understanding "Diffusion” and construction leaks into buildings.  

• The following information is "on average" and used to illustrate how moisture enters our buildings. Current diffusion rates due to product improvements may differ.

• Definition: diffusion refers to the movement of water vapor through materials due to differences in vapor pressure. This process occurs even in the absence of air leaks and is driven by the tendency of water vapor to move from areas of high vapor pressure to areas of low vapor pressure. Understanding vapor diffusion is crucial for managing moisture in buildings and preventing issues like condensation and material damage.

• Warped flooring, mold, discolored flooring and subfloors, so many indicators you can confirm with moisture meters when used correctly. Unfortunately, many flooring contractors fail to use moisture meters and hygrometers that are available to them to avoid costly replacements of flooring, that steal their profits. 

• In the diagram above, that is just one 4' X 8' gypsum panel or board. How many are in a construction site? There are building wraps and you say, OSB o r plywood? 

• Here you go: (osb and plywood) Class II or Class III vapor retarder category, with perm ratings typically ranging from 1 to 5 perms. House wraps: acts as a weather-resistive barrier installed under siding. It's designed to be water-resistant to prevent bulk water intrusion into the wall assembly, while also allowing water vapor to escape from the inside, preventing moisture buildup and potential rot or mold. General Perm ratings suggest by some building experts suggest that a perm rating between 10 and 20 is ideal for balancing moisture management in a wall system. Some popular brands can have as much as a 56 perm rating. The goal is moisture control in the walls. 

• Now, back to what can happen to our floors.

If there are holes leaking air into our buildings, water is not far behind.

• Look at how much can happen with just the one hole, whatever type of wall panel. What is there are gaps in the wall wraps? holes punched in the wraps? Possibly, hundreds of small holes! 

• This is why understanding "Psychometrics" is important: it is the study of the thermodynamic properties of moist air, primarily focusing on air-water vapor mixtures. The study of Psychometrics involves analyzing how temperature, humidity, and other factors interact within a space. 

• You can be blamed for construction defects! You need to know how to find moisture sources to PROTECT YOUR PROFITS. 

• This is important information you should know to understand problems you encounter but more important, prevent. Using the right tools and meters, and how to use them, can save you money and prevent costly callbacks. 

• We recommend two meter companies, Tramex and Delmhorst, and each has wall probes (that can be used for many purposes) and attachments that can be slid under quarter rounds and wall bases to help measure moisture diffusion. Guild students receive a direct discount from the companies.